Authors of this study have been investigating for about 20 years the criteria of fish food selections by human populations, Â represented by small-scale fishing communities in Brazil (coastal and riverine). These investigations were supported by several FAPESP projects. The diet of human populations reveals to a great extent how humans interact with nature and exploit natural resources. Thus, both anthropologists and human ecologists have been studying food categorization and choices. Authors of this study case use a human ecology approach to address these questions.

Studies reported in this paper were supported by FAPESP and IDRC. The authors have investigated important parts of the diet of human populations regarding food choices. They have analyzed a decision making process in exploiting an available food resource related to the relative effort spent on food preparation/manipulation, and the possible attainable profit. In particular, manipulation effort is represented by the time spent in the process of fish consumption effort. Large manipulation times leads to lowering of the respective value of particular food source. Then, the respective value of a particular fish can be represented both ecologically, by decisions fishers have to make (when choosing less bony fish as target species), and economically, Â by the price of fish in the market ( since high manipulation time is represented by lower fish prices;Â less bony fish also shows higher market prices).

The case study published in the Brazilian Journal of Biology is on fishers from two communities of the municipality of Paraty, Rio de Janeiro: Praia Grande and Tarituba. We interviewed 73 inhabitants: 44 at Praia Grande (15 men and 29 women) and 29 at Tarituba (14 men and 15 women). Authors observe, as following:

“Robalo (snook, Centropomus spp.) was the fish most cited as eaten by all interviewees, and it has the highest price in the markets of both communities. Fish with fewer bones are preferred for commercialization. Bony fish seems to be at the bottom of the usefulness by all interviewees. The most appreciated fish (preferred to be eaten) are also the less bony fish”.

Authors stress the importance of fish choice by fishers for purposes of management and food security. Since fishers should choose between consuming or selling the catch, they end facing a dilemma of household versus market. The market exerts pressure to sell the most valuable fish, but households prefer to consume less bony fish. Thus, target species are often limited with commercial, highly valued fish. Other factors should be also taken into account, such as management processes: one should take into account periods when fishing is not allowed for some species. It can lead to high potential impacts on the food security of families. Finally, one can conclude that food choices, as predicted by optimal foraging models, are not just part of the culture. They can be influenced by biological attributes, such as fish boniness, and, as this study has shown, by the time and effort required for food (fish) manipulation.